Core drill



Jul 24, 1928. 1,677,925 J. S. MITCHELL CORE DRILL Filed Nov. 1923 13 .1. -8

Patented July 24, 1923. A

UNITED STATES PA-TENT OFFICE.

lI'OSEPH S. MITCHELL, OF CHlICAGO, ILLINOIS, ASSIGNOR TO SULLIVAN MACHINERY COMPANY, A CORPORATION 01 MASSACHUSETTS. 7

CORE DRILL.

. Application filed November 5, 1823. Serial 110. 872,785.

' My invention relates to core drills.

It has for its object to provide an improved core barrel and more particularly an improved core barrel having an im roved connection to the core barrel head w ereby the threaded connections and the necessa weakening resulting therefrom is eliminate A further object of my invention is to provide an improved method of making core barrels whereby the above objects are obtained.

In the accompanying drawings I have shown for purposes of illustration one form which myinvention may assume in practice. v

In these drawings,- v

Fig. l is a side elevation of a core barrel constructed in accordance with my improvement;

Fig. 2 is a artial vertical sectional view showing my improved connection of the barrel tubin to the head.

In this ihustrative construction I have shown a core barrel of a standard construction used in oil well work, which need not be more specifically described than to say that it comprises a fluted diamond bit 1 and fiutted guide 2 operatively connected to the core barrel tubing 3, this tubing 3 in turn being connected to the core barrel head 4 in an improved manner hereinafter described.

In my improved construction the end of P the core barrel tubing 3 is turned to a driving fit as shown at 5 and a groove 6 is formed in the head 4 at a point intermediate the ends thereof and preferably at the inner end of a reduced portion 7 below its usual threaded portion 8 and adjacent a portion [m turned to corres nd to the ortion 5 of the turned end of the barrel, the upper end of the tubin 3 is peened into the groove in the g head, and the groove, made by the'peening in the member 3 and by the adjacent shoul- 'der on the head, is filled with welding material, and the whole welded. ,In a preferred form, to prevent relative rotation a plurality of transverse drill holes 9 is also provided through the member 3 and part way through the portion 7 of the member 4, as indicated, below the peenin and these holes are likewise filled w1th we ding material before welding.

As a result of my improved'construction it will be observedthat all threading between till barrel. Then t e head is riven into the the core barrel tubing and the core barrel head is eliminated with a resultant elimination of the weakening due to the necessary cutting away of the metal in threadin and a consequent elimination of the breaklng of the core barrel at this joint, a construction being produced in which there is more metal and therefore more strength at the joint than at any other part, this at the same time that the desired uniform external diameter is maintained, the-use of the welding material tending to produce an entirely smooth exterior.

While I have in this application specifically described one form which my 1nven tion may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and'that the invention may be modified and embodied in yarious other ,forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is 1. A core barrel comprisin a head formmg a drill rod connection an having a circumferentially extending groove formed on the periphery thereof, and a plurality of recesses, a tubular core receiving barrel member having a drive fit with said head and havin its extremity adjacent said head eene into said groove partially filling the latter, said barrel member having perforations in registry with said recesses, and bodies bf metal in theunfilled portion of said groove and in said perforations and recesses and welded to the adjacent portions of said head and barrel member respectively.

2. A core barrel comprising a head forming a drill rod connection, said head having a shoulder, a circumferentially extendin oove formed on the periphery thereof a acent said shoulder, and a recess, a tubular core receiving barrel member fitting said head, the extremity of said barrel member adj acent said shoulder being peened into said groove partially filling thelatter, and a perforation in said barrel member in re ry with said recess, and bodies of metal in the unfilled, portion of said groove and in said erforation and recess and .welded to the a jacent portions of said head and said barrel member respectively.

3. A core barrel comprising a head forming a drill rod connection and having a 1 shoulder, a reduced portion, said reduced portion having recesses formed therein, and a circumferentially extending groove formed on the periphery of said reduced portion adjacent said shoulder, a tubular core reregistry with said recesses, and bodies of.

metal in the unfilled portion of said groove and in said perforations and recesses and Welded to the adjacent portions of said head and barrel member respectively.

4. A core barrel comprising a head forming a drill rod connection and having an en.- larged internally threaded portion and a re duced portion, said reduced portion having recesses formed therein, and a circumferentially extending groove formed on the periphery of said reduced portion adjacent the lower end of said threaded enlarged portion, a tubular core receiving barrel member having a drive fit with said reduced portion and having its extremity adjacent the lower end of said enlarged portion peened into said groove partially filling the latter, said barrel member having perforations in registry with said recesses, and bodies of metal in the unfilled portion of said groove and in said perforations and recesses and welded to the adjacent portions of said head and barrel member respectively.

In testimony whereof I affix my signature.

JOSEPH S. MITCHELL. 

